1. Field of the Invention
The present invention relates to a mobile communication terminal and a position monitoring method.
2. Description of the Related Art
The mobile phone has a feature enabling a positional search of the mobile terminal by a separate terminal in order to ensure the safety of the mobile phone owner or to verify the location of the mobile terminal. For example, there is a system wherein the location of a sub terminal can be verified by the main terminal by the terminal transmitting positional information to a monitoring center in response to a command from the monitoring center or transmitting positional information every predetermined time (for example, refer to Japanese Patent Laid-Open Publication No. 2003-18635)
Furthermore, with the mobile terminal equipped with the above-mentioned feature, a method can be considered wherein the current location can be transmitted to a monitoring center unit when the mobile terminal owner wishes to notify his location at a time of an emergency even when the power switch is turned off or if an emergency button is manipulated (for example, Japan Patent Laid-Open Publication No. 2002-209248)
In order to continue the foregoing positional search for an extended period of time, reduction of power consumption of the terminal is vital.
However, the technology described in Japanese Patent Laid-Open Publication No. 2003-18635 above is a proposal regarding the transmission timing of positional information and there is no mention of a positional search mode for further reducing power consumption.
Also, the technology described in Japan Patent Laid-Open Publication No. 2002-209248 above is a proposal for forcibly continuing positional search after the power has been turned off, and in this case, there is no mention of a positional search mode for further reducing power consumption in comparison to operation when the power is on. In particular, there is no proposal which takes into consideration reduction of power consumption under the assumption of a mode primarily using positional search when the positional search feature is provided with a mobile phone as an additional feature.